"""Think about it logically — the Russians were ahead of the Americans for most of the space race but they pulled out and never made it to the Moon. They must have known it was impossible".

I defy anyone to show me any principle of logic which supports this statement.""

Well, the first thing to do would be to rewrite his informal statement into standard syllogistic form. I know that he didn't write it in this form, but I believe what he wrote has the same meaning, and that it would be intellectually dishonest to condemn his presentation of his argument for failing to meet logical standards while ignoring whether the actual intended meaning of his argument does. Thus, as a syllogistic string, his argument should look like the following.

Premiss #1 If it were possible to put a man on the moon, the Russians would have done so.
Premiss #2 They didn't.
Conclusion #1 It must have been impossible to put a man on the moon.
Premiss #3 If one claims to do the impossible, they are lying.
Conclusion #2 If one claims to have put a man on the moon, they are lying.
Premiss #4 The US goverment claimed to put a man on the moon.
Conclusion #3 The US government was lying.

When examining this, keep in mind that logic can't tell us whether any premisses are true, it can't even tell us if our conclusions are true. They ONLY thing it can tell us is whether our conclusions are NECESSARILY true IF our premisses are true. (You might want to reread that, it's a very important point to understand if you wish to be a logician). When that is the case, that our conclusions must be true if our premisses are true, then we are being logical.

With this argument if you accept the premisses, you must accept the conclusions. I demonstrate...

The first part of the string is a modus tollens argument, which logicians have defined as valid. It follows the format of "If P then Q. Not Q, therefore not P."
In this case it goes "If it were possible to put a man on the moon, the russians would have done so. The russians didn't do so, therefore it was not possible to put a man on the moon."

The second part takes the conclusion from the first argument and adds a new premiss, forming a modus ponens argument, which is also valid. It follows the form of "If P then Q. P, therefore Q." In this case it goes "If one claims to do the impossible, they are lying. It was impossible to put a man on the moon, therefore anyone who claimed to do so was lying." (Note that in this case I reversed the order of the premisses, which is a perfectly valid thing to do)

The third and final part of the argument has the conclusion from the second part and adds one more premiss to it. Again, it's in modus ponens form, "If p then q, p therefore q". This time it goes "If one claims to have put a man on the moon they were lying, the US govt. did so, therefore the US govt. was lying."

The entire argument is logically sound. That means that in order for it's conclusion to be wrong, one or more of the premisses leading to it must be untrue.

Now before you start attacking the first premiss as being untrue, I want you to go pause for a minute and think about what you just did. You called the reasoning to an argument faulty because you didn't like it's conclusion. Shame on you. Go to your room! And don't come out until you can say you're sorry!

And when you do apologize for that, and admit it was evil of you to suggest that an argument was illogical simply cause you didn't like it's conclusion, then we can talk about whether premiss #1 is true. Personally, I think it isn't.

A couple other things before I end this.

In the "Logical deductions" portion of the page you make reference to the Holmes maxim "When you have eliminated the impossible, whatever remains, however improbable, must be the truth." as being one commonly used by moon hoax believers. I assume that means they are claiming that if you prove it impossible for the US space program to have gone to the moon, than the only other option is that they faked it.

You claim this fails ON LOGICAL GROUNDS because of two reasons.

"1. The theory makes no realistic effort to find or eliminate all other possible explanations."

Again I want to mention that logic only tells us if our conclusions follow from our premisses. If we accept the premiss as true that NASA couldn't have put a man on the moon, what explanations other than they faked it need to be "found" or "eliminated"? Anything that is more likely than they faked it, assuming they didn't go?

"2. Even if other explanations could be eliminated, there is no logical process which leaves a hoax as the only remaining possibility."

This is self-contradictary. Either you've eliminated the other possibilities and there's only one left or you haven't. There's no "even if you eliminate all the other possibilities you haven't narrowed it down to one".

In the "Burden of Proof" portion you ask "Whose responsibility is it to prove that the moon landings were real?" You follow this with a claim that "There is a principle which states: The person proposing a theory has the burden of proof."

That principal, whether it is held by logicians or not, (I've never heard of it, but it wouldn't surprise me if a lot of the new-fangled internet logicians have subscribed to it), is wrong. Outside of a courtroom, there is no such thing as a "burden of proof". In a logical debate, (the only kind you should try to have), people should present all of the evidence they have for and against any conclusion, whether it's the one they believe or not. Then they should look at the evidence with a detached mindset, and see what it says is most likely true. These "burden of proof" debates in which people argue over whether or not they should be required to support their beliefs with any evidence is anethema to logic.

Your statement further down the page says "When evaluating a theory, don't just ask if the conclusion makes sense based on the evidence provided. Ask whether the logical process has been correctly followed."

Um... if the conclusion "makes sense", (or more properly definitively follows), based on the evidence provided, the logical process HAS been correctly followed. In a rather belated interest of brevity I'll end here.

PS - please don't feel angered or attacked by this. My intent is to educate, not to mock or instigate.

I would never feel angered by rational debate. Thank you for your input, there is lots to consider there. I wish I could do you the courtesy of a decent reply but right now I'm very busy and I can't afford the time to go over your message in detail. I will do so as soon as I can.

First of all, I suppose I interpreted the writer's logic a little differently, i.e.:

Premiss #1: The Russians were ahead of the Americans for most of the space race.
Premiss #2: The Russians pulled out of the space race without explanation.
Conclusion: Landing on the Moon is impossible.

I think I'm correct in saying that this is logically unsound. However my challenge was to show any logical process which would support what the writer was saying, and I accept that you have indeed provided a valid logical argument which does so.

I don't think it's fair to say that I dismissed the logic simply because I don't like it's conclusion. I think I had genuine cause to dispute the logic as I interpreted it. When the logic is re-written as you have done, I cannot dismiss it and I accept that (without any apology).

I guess if I wish to refute your logical conclusion, my only option is to refute your premiss "If it were possible to put a man on the moon, the Russians would have done so." Do you agree?

In regard to your extensions of the argument, I do not dispute any of what you said.

Regarding the Holmes rule, my point was that it is not actually valid to use this as a tool of logic in the first place. It irks me that people use the Holmes rule as if it was the foundation of all logic. To quote myself, "The underlying problem is actually the use of the Holmes Rule at all. Although it sounds very logical, this maxim is only useful in a limited number of situations...".

Regarding the "burden of proof", what I wrote in that section stemmed from a discussion with a group of lawyers. I followed up with some (very casual) research and found that this principle is generally accepted in legal and scientific circles. Perhaps I was wrong to include this in the page about logic but it just seemed the best page to dump it (you will note that I never claimed it was a principle of logic, just a principle). Again, I will reconsider the way I have worded this section.

In fact I will reconsider the whole page in light of what you've said. I can't do it right now but I will make every effort to revise it as soon as I can. Naturally I will remove my logic challenge now that it has been met.

I would like to thank you again for your detailed message. It certainly is a breath of fresh air to see someone embracing critical thinking. In this day and age it's easy to become disillusioned with the amount of dribble that passes for arguments on the Internet.

Finally, I have a question. Some time ago I had an idea for a website which would serve to independently examine the logic of various arguments, writings, claims, etc. I envisaged it as a public service to counter the rampant lack of critical thinking in our society. It would work something like this:
- Members of the public submit material to be judged, for example, a politician's speech justifying a war or a church leader's reasons why Intelligent Design should be taught in science.
- A moderator approves worthwhile submissions and rejects frivolous rubbish at their discretion.
- A panel of logicians rate the material on it's logic, providing comments and perhaps an overall score (tacky but scoring has appeal).

I have the resources to set the site up and I have some good ideas about how it could be run and promoted, but I lack the expertise to do the actual logic testing. What the site would need is one or more people such as yourself who are well-versed in the application of logic. Do you think that you, or anyone with your skills, would be willing to participate in such a project? It's possible that there could be a modest income for panelists but we'd need to proceed on the assumption that it is voluntary.